Device for manufacturing elastic joints



Aug. 25, 1936. 4 0. D. J. c. c. COLAERT 2,052,443

DEVICE FOR mauumcwuame ELASTIC JOINTS- Filed Oct. 23, 1935 2 Sheets-Sheet 1 mum pvvarv 1936- I D. D. J. c. c. COLAERT 2,052,448

DEVICE FOR MANUFACTURING ELASTIC JOINTS Filed Oct. 2-3, 1935 2 Sheets-Sheet 2 7/11IIIIIIIIII/IIIIIIIIIIA Patented Aug. 25, v 1936 UNITED STATES.

nsvrcn .ron MANUFACTURING nus-no JOINTS Daniel Dominique Joseph Charles Oorneilio Coiaert, Hazebrouck, France Application October 23, 1935, Serial No. 5.239% In France November 8, 1934 7 Claims. (01; 205-4) This invention is relative to a device for manufacturing elastic "joints, constituted by two concentric metal muffs (or by an axle surrounded by a muff) between which is inserted a. rubber ring, 5 which is strongly compressed in a manner to adhere to the surfaces of both said muifs and to be presented from sliding.

Among the known methods of manufacturing Joints of the described kind, some consist in inserting by force between the two concentric mufis a rubber ring, the thickness of which is greater than the annular space existing between said muffs. Such an insertion is obviously however very dimcult to perform. In order to obviate this difficulty, it has been suggested to force the-rub:-

ber ring onto the inner mud then to draw it out in axial direction until its outer diameter is suiiiciently reduced to permit the outer mud to be mounted with but small friction, and finally to let 2d the rubber ring loose.

A second method, which naturally comes to mind consists in using a rubber ring, the thickness of which practically does not exceed'the annular space comprised between the two metal 2b mufis, so that it may be introduced therein with but small or even without any compression, and,

to perform its strong compression but subsequent- 1y, either by reducing the diameter oi the outer muff, or by extending that of the inner mud. Such .30 reduction of the diameter of the outer mufif waseflected however by means of special raising in machines, this being a fairly long and delicate operation, in which a regular radial compression of the rubber ring is dimcult to obtain.-

It has also been suggested to reducethe diameter of the outer muff by drawing it out, but this discloses the drawbacks of increasing the length oi said muff and diminishing .its thickness, conse quently reducing its strength, on'one hand, and on the oth'rgi' of causing considetable waste of material, as the drawn out ends of the muff must be out oh and go to scrap. Object of this invention is to provide a device lor performing the second of the hereinafter mentioned methods while avoiding the drawbacks oi raising in or drawing out one of the metal frauds or the joint; this device is characterized in that it comprises two members, one of which is fixed and the other movable, and that one of said memhers is conically shaped and adapted to modify the diameter of one of the metal muds of the joint, whereas the other member is elastically deformable in diametral direction in amannerto 55 follow the progressive deformationoi the diameter of the deformed metal mufl.

This device discloses, amongst other advantages that of providing the outer metal mui! witlr a very great hardness and elastic limit, whichcould not be produced by any thermic treatment,

which is moreover, inapplicable in the present instance.-

Two embodiments of the device object of the invention are hereinafter described, by way'oi examples, with reference to the accompanying 6 drawings:

Fig. l is an atrial sectional view of the joint in its initial state.

t Fig. 2 illustrates e first phase cl its manufac- 10 his. 3 is elevation sectional view of the conically sped member of the device;

his. t is a similar view of a push-member for pushing the Joint through the comically shaped member. 15

his. 5 is a view ot a detail oi said push-member.

Fir. s illustrates the device in work;

Fla. 7 shows the in bed joint;

big. a illustrates a second emboent oi the device according. to invention, which extends the diameter of the inner mud or the joint.

Fla. 1 illustrates, in longitudinal section, the three members lorming the joint, which are adapted to set into position without any dimculty belore the ul 1 i:- a ng of the operation. The outer not yet deformed metal mud is shown in i, the also not delormed rubber rinr in l, and the inner member oi the joint, which may be con stituted by a hollow mud, or, it so desired, by a. full aisle, ternated for instance by conical, cylindricsl or square heads, and a threadinr, etc., is shown ml.

'lhe setting cl rubber rin on the smaller mud ay be facilitated, as shown in Fla. 2, by means of a device lrnown per'se, such as a conicaliy shaped member d, provided with'a cylindrical portion l. which his into the bore ol the tube l and forms a gentle slope, on which may slide the rubber rinwdi when itds too narrow, so as to reach the outer dieter oi the small mud l, 40 this cone is thdra ter the ring is set into ition.

The dimeons ol the metal mud l, as well as those oi the elmtic ring l are calculated in a manner that the mud i after having been deformed in the. device jobiect oi the invention should have the enact predeteed final dimen sions, and that the rubber rin should at that time have reached the desired degree oi radial compression.

The device permitting to delorm the outer mud l at the joint comprises essentially a die t (Fig. 3), the bore of which is formed:

'(a) by ashort conical entry l (b) by a cylindrical portion 0 5b (0) by a lone conical portion 9, and

(d) by a cylindrical portion to.

The diameter of the cylindrical portion 8 is equal to that of the outer metal mufl I. (Fig. 1) with allowance: permittinc the mull to slide verticaly therein without play. The dimensions of the cylindrical portion II) are equal to the desired final dimensions of said muff I. These two cylindrical portions are connected by an intermediate truncated portion 9, which is sufliciently long to provide a gently sloped connection between the bores 8 and ID. The slope is of about 5 to 7% to the diameter, and the length of the bores 8 and I is equal at least to one third of the length of the outer muff of the joint.

The inner surface of the die is converted, tempered and rectifiedby grinding according to the degree of precision which is necessary for the finished joint. The body of the die 6 .is provided with a bearing II, which enables it to be fixed in the mortise of a press frame.

The push-member for forcing the joint through the die 6 is constituted (Fig. 4) by a steel rod I2, provided at its end with a slightly conical tubular portion I3 which is slotted according to two diametral planes perpendicular to one another, so as to form four slots such as I4. This tubular portion I3 of the push-member is slightly conically shaped, its diameter increasing downwards. The upper end of the push-member is provided with a screw-threaded head I5 and a bearing I6, which enable said member to be fixed onto the movable member of a press or of any other device, adapted to produce a thrust in a direction perpendicular to the frame in which is fixed the die. In a circular groove of rectangular section provided in the lower portion of the push-member, is located without play a ring I! in bronze or any other soft metal or alloy. This ring, illustrated in Fig. 5, carries a sliding articulation I8, enabling it to widen or to shrink during the operation.

The outer diameter D of the ring I! is equal to that of the bore 8 of the die 6, and the total width of the four slots I4 of the push-member i3 is equal to at least the difference between the lengths of the circumferences B and III of the die.

Fig. 6 illustrates in way of manufacture a joint, the inner member of which is constituted by an axle 2', with conical heads I9 and screw threaded portions 20, instead of being a tube., The rubber ring having been set into position between the members I and 2', as illustrated in Fig. 1, adjacent to the end of these members, the joint is inserted vertically by hand into the die 6, by its end on which is set the rubber ring 3. The press is then set into action, and its movable portion 2i is lowered together with the elastic push-member screwed therein. The end of the push-member bears against the outer tube I, and forces it through the conical portion 9 of the die 6, the elastic slotted tube l3 being deformed while passing through said die. The outer circumference of the mud I is therefore forced to decrease progressively according to the cone 9, until it reaches the diameter of the cylindrical portion II) of the die. As the length of the muff,

during said forced reduction of its outer diameter is unable to increase, because of the continuous thrust of the elastic member I3 on the metal, the thickness of said muff is forcibly increased, and its original internal diameter (Fig. 1) reduced by:

(1") the difference between the diameters of the bores 8 and III of the die.

(2") by a quantity resulting from the additional thickness acquired by the outer metal mufi at its exit from the die.

When the elastic push-member I3 passes through the cone 9 its slotted conical portion shrinks under the action of the bronze ring II, which, owing to its sliding articulation, adapts itself exactly to the ever decreasing circumferences of the conical portion of the die, and the original width of the slots I4 (Fig. 4) is reduced to zero. The bronze ring I! discloses the advantage of not impairing the inner surface of the die and of being easily replaced when worn out. There is no need for this ring to be elastic, as when passing through the die it is forced to shrink by the conical portion of same, and as outside the dieit is forced to open by the clasticityl of the conical portion of the pushmember 3.

The annular space comprised between the metal muffs I andZ is thus reduced during the operation while passing through the die so that the elastic ring 3, the outer diameter of which has been progressively reduced, has also been drawn out (Fig. 6) and finally fills up entirely the final annular space. The finished joint has the aspect illustrated in Fig. '7- the rubber being.

everywhere uniformly compressed in radial direction. When the outer muff I engages at the start of the operation, in the conical portion of the die, the elastic ring 3, which is immediately deformed startingfrom its face 22 (Fig. 6) adheres owing to its compression sufficien'tly to the two muffs, so as not to be able to slide backwards.

The difierence between the inner diameters of the muff I, before and after the operation, is proportional to the desired deformation of the rubber ring 3, and varies according to the intended use of the joint. By setting the final dimensions of the outer muff, the volume of which is:

R1 and n being the radii of the muff I before the operation, R and r the radii of the same muff after the operation, and L its length.

and T! is equal to the radius of the finished mufl', increased by the difference between the primltive" and final" radii of the rubber ring, as it is this difference which determines its degree of compression.

The described operation results in the hammerhardening of the metal of the deformed muff, the mechanical characteristics of hardness and elasticity of which are thus increased. Moreover, the joint is expelled from the apparatus at its desired final dimensions with a precision of 1/100 of a millimetre, without having to be corrected and the outer surface of the muff I being fully polished and without any marks.

For joints of small resistance, that is to say for such the diameter of the outer muff of which is but weakly reduced, say by 2 mm. one single operation may suffice. When placing the three members (Fig. l) the two metal muffs I and 2 and the rubber ring 3 should be set in respect to one another, allowing for the recoil motion of the two latter members, which varies with the reduction of the diameter when passing through diameters. The rubber ring 3 is then placed bev tween the two metal muffs on their middle portion, and at each subsequent passing through a die, the joint is turned over, so that the end entering into the subsequent die should be that which came out last out of the preceeding die.

The joint passes through dies of ever smaller diameter, the second die termed intermediate die" being provided with an entrance bore of a diameter equal to that of the exit bore of the first die, termed rough-ing down die, the entrance bore of the third die being equal to the exit bore of the second, etc.

Another embodiment of the device according to invention, but which may be used only for such joints, the innermember of which is constituted by a. hollow tube, is illustrated in Fig. 8 of the accompanying drawings.

A tubular elastic buffer 23, provided with slots 24, similar to the elastic push member l3,'but provided at 25 with a recess, is mounted inside a guiding frame 26, and in'said recess is placed a joint as shown in Fig. 1. A mandrel formed by two cylindrical portions 21 and 28, connected by a conical portion 29, is pushed down vertically by the movable member.of a press 30. When passing through the muff 2, the mandrel deforms it by increasing its inner and outer diameters. It is clear that the annular space between the two muffs is reduced and is filled up by the compressed elastic mass of the ring 3.

This embodiment requires more time, as after each operation, the mandrel must be retrieved and placed at the entry of the muff 2, whereas it is expelled from the apparatus through the aperture 3|.

The mandrel may be replaced by a simple ball, the operation remaining the same. The inner tube may also be progressively extended by using mandrels or balls-of ever increasing diameters.

What I claim is: 1.41;.

1. Device for manufacturing" elastic joints of the kind comprising a. cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device compris ing a conical membeig-adapted to modify the diameter of one of the metal members of the joint, a diametrically .elastic member, one of said members being 'fixed and another being movable along its axis, means for forcing said elastic member to follow the variations of the diameter of the deformed member of the joint.

2. Device for manufacturing elastic joints of the kind comprising a cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a fixed conical member adapted to modify the diameter of the outer metal mufi of thejoint, a diametrically elastic member movable along the produced axis of the cone of said first member, means for forcing by said elastic member the outer member of the joint throughout said fixed conical member.

,3. Device for manufacturing elastic joints of the kind comprising ;a cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a movable conical member adapted to modify the diameter of the inner member of the joint a diametrically elastic member fixed in the produced axis of thecone of said first member means for forcing, said conical member throughout the inner muff of the joint, means for supporting said inner member of the joint by said elastic member.

'4. Device for manufacturing elastic joints of the kind comprising a cylindrical metal inner memben'an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a fixed conical die adapted to modify the diameter of the outer metal member ofthe joint, a metal rod adapted to move coaxially to said die and to drive the joint through said die, a tubular conical portion at the end of said rod, said tubular portion provided with slots and also having a circular groove of rectangular sec.- tion, and a metal friction ring in said groove and provided with a slidable articulation.

5. Device for manufacturing elastic joints of the kind comprising a cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a fixed die adapted to modify the diameter of the outer muff of the joint, said die comprising a short conical entrance, a cylindrical portion of a diameter equal to the original diameter of said outer mufi, a cylindrical exit portion of a diameter equal to the final desired diameter of the joint, a conical portion connecting said two cylindrical portions, a metal rod adapted to move coaxially to said die and to drive the joint through said die, a tubular conical portion provided at the bottom of said rod, said tubular portion having slots and provided with a circular groove of rectangular section, and a metal friction ring in said groove and provided with a slidable articulation. 1

6. Device for manufacturing elastic joints of the kind comprising a cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a movable conical member adapted to modify the diameter of the inner member of the joint, a fixed conical tube mounted coaxially with said conical member, said tube having slots ex tending along its generating lines and also having arecess adapted to receive the end of the inner member of the joint.

7. Device for manufacturing elastic joints of the kind comprising a cylindrical metal inner member, an outer metal muff concentric with said inner member, and an elastic ring compressed between said metal members, said device comprising a movable mandrel adapted to modify the diameter of the .inner muflf of the joint, said .mandrel comprising a cylindrical portion of a diameter equal to the original diameter of the inner muff, a cylindrical portion of a diameter 

